I’m saying it would be a waste of their time.

Why exactly? Catching trolls is much easier on popular sites like the ones you listed. Sure, there are more of them, but also more of them are constantly flagged. Fediverse has no such overarching moderation, as you well know.

You don’t see how that’s a massive advantage?

I hope you don’t need another reply to understand, you’ll have to ask someone else.